


Baby, It's Cold Outside

by RealOrNotInspire



Series: Christmas One Shots [7]
Category: Chicago Fire
Genre: Christmas Smut, M/M, NSFW, One Shot, Poker Night, Sexual Tension, Song Inspired
Language: English
Status: Completed
Published: 2020-12-01
Updated: 2020-12-01
Packaged: 2021-03-10 06:14:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,373
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27819592
Author URL: https://archiveofourown.org/users/RealOrNotInspire/pseuds/RealOrNotInspire
Summary: It’s that time again! It’s been a crazy and stressful year, more than usual but let’s end this year right with December Sevasey.Never thought I’d write song inspired smut but here we are. I may have ruined a Christmas song or maybe I made it better, let me know. Fair warning this is NSFW it got way - way more smutty than I originally expected.
Relationships: Matthew Casey/Kelly Severide
Series: Christmas One Shots [7]
Series URL: https://archiveofourown.org/series/1562035
Comments: 15
Kudos: 50





	Baby, It's Cold Outside

**Author's Note:**

> I know I’ve been gone for a long time and yes, it’s still gonna be a minute before there’s an update on the ‘Long Love Story’ but I do have a whole bunch of Christmas stuff to post until I can crack this evil chapter that’s been taunting my writers block.

It’s Severide’s turn to host this month’s poker night and Casey almost hadn’t gone, a little over a month ago they’d fallen victim to Chili’s ‘Volcano Theory’ a high intensity shift, leading to a hook up to ‘blow off steam’. They’d agreed it was a one-time thing and it didn’t need to change anything between them and most importantly that no one at 51 needed to know about it. But that was easier said than done and Casey was having a hard time staying away from Severide, the magnetic pull of the man’s charm was hard to resist and Sev wasn’t even trying to hide it. Flirting anytime they were alone and asking if he wanted to grab breakfast or go for a drink anytime they were off shift, meaning Casey had made a point for them to never be alone in a room together.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

“I think it’s time to call it a night, gentlemen.” Boden says, checking his watch and finding it two hours later than he thought it was, Donna was not gonna be happy.

“Agreed, someone cash me out, I’ve needed to piss for over an hour.” Casey agrees, leaving the table.

“Why didn’t you just go?” Otis asks confused.

“You never leave the table when you’re on a hot streak.” Boden explains around the last of his cigar, Severide, Cruz and Herrmann nodding at the words of wisdom.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Coming back from the bathroom Matt finds Kelly clearing empty beer bottles and everyone else already gone. Looking back to where he just came from Matt asks. “How long was I in there?”

Kelly just chuckles, asking. “You want another beer?”

“Uh, no, I should probably go.” Matt shifts on his feet, knowing that they were playing with fire.

“One more beer, what’s the worst that could happen?” Kelly says like it’s harmless, holding out a beer but Matt doesn’t take it.

“You know what could happen Kelly.” Matt sighs, stepping back and putting extra space between them.

“That was weeks ago.”

“And this is the first time we’ve been alone in weeks.”

“You worried it’ll happen again?” Kelly teases, closing the distance Matt had created, leaving them in arms reach of each other.

“Yes, Kelly. I am.” Matt answers Kelly’s teasing honestly.

Closing the last of the space between them Kelly steps into Matt’s personal space and rests a hand on his hip. “Or. Maybe. Do you want it to happen again?”

“Kelly.” Matt sighs.

“I want it to happen again.” Kelly’s voice dropping deeper as he whispers in Matt’s ear.

“I really should go.” Matt breathes, feeling himself getting sucked into the moment and knowing what would happen if he didn’t leave.

“One more beer.” Kelly all but begs.

“I should call a cab.” Matt trying to convince himself more than Kelly.

“Look at the snow. It’s practically knee high, you’ll never get a cab. You should stay the night.” Kelly reasons.

“I should say no.”

“At least don’t go so soon. One more beer?” Kelly asks again, his lips so close to Matt’s, he’s about to close the gap when Matt says the magic words.

“Maybe just one more.” Matt doesn’t know where the words come from, looking deep into Kelly’s eyes he feels himself falling further under the man’s spell. He wished but knew how to break this spell Kelly had over him but at the same time he feels every fibre of his body wanting to give over to it.

“You wanna put some music on?” Kelly smiles seductively.

“Don’t push it, Severide.” Matt chides, taking the offered beer from Kelly’s hand and putting the space back between them as he begins to think clearly again.

“Wanna finish your cigar?” Kelly offers.

“Sure.” Kelly lights the cigar for him, leaning in close to do it, the sexual tension building up again.

Matt makes a point not to sit on the couch, imagining Kelly on top of him or himself straddling Kelly if they sat next to each other. So he leans against the dining table that they used to play poker on, Kelly sitting on the arm of his couch and facing him, the signature Kelly Severide smirk on his lips as he smokes the last of his own cigar.

They’re locked in a silent, intense staring battle until Matt can’t take it anymore and finally asks Kelly. “What you looking at?” He doesn’t expect the answer he gets.

Kelly waits until Matt has the bottle to his mouth before answering bluntly. “Your lips.”

Matt almost chokes on the last of his beer, putting the bottle down and standing to leave when Kelly’s suddenly standing right in front of him, leaving him trapped between the table and Kelly’s warm, inviting, well-muscled body that he can barely resist touching, his self-control hanging by a thread as his knees start to feel weak.

Kelly backs Matt up further to sit on the table so he can slide in between the man’s legs. His voice is deep and husky as he seduces Matt further. “I remember how your lips felt, so soft against my skin.” Kelly running his thumb over Matt’s lower lip as he speaks. “The way you bit your lower lip. And then the noises you made when you finally let go.” Kelly groans at the memories his own words bring up.

Matt can feel himself getting hard at Kelly’s words, feeling the man’s own matching hard on pressing against his inner thigh but still there’s one part of his brain holding out, telling him that there’s no coming back from this, tonight could change the nature of their relationship forever. And even as he feels the thrill run up his spine, as his body cries yes and he knows how long he’s wanted this, he just didn’t know what would happen after. His worst fear was that if they crossed this line and it didn’t work out, that he’d lose Kelly forever. 

“I should leave.” Matt breathes, his fears making one more attempt to stop them from crossing this line.

“Please, don’t go.” Kelly begs. Matt can feel the warm breath on his cheek, a stark contrast to the cold weather he knows is waiting outside.

“I really shouldn’t stay.”

“Baby, it’s cold outside.”

“We said it was a one-time thing.”

“I know you hate the cold.”

“It’s getting late.”

“Then stay.”

“51’s gonna talk.”

“Let them.”

“Kelly, I’m running out of reasons to leave.”

“Then shut up and kiss me.”

“At least I’m gonna say that I tried.”

“Matt, shut up and kiss me.” Kelly cups his cheek but leaves the final move up to Matt, never wanting to force him into something he didn’t want. Matt’s resolve crumbles and he can’t hold back any longer, their mouths crashing together in a clash of tongue and teeth as they instantly start tearing at each other’s clothes. Quickly losing their shirts, Matt wraps his legs around Kelly who lays him back on the table, feeling Kelly’s hands running up and down his chest as he kisses his neck to the sound of poker chips scattering across the hardwood floor.

Kelly moves to kiss his way down Matt’s chest, stopping to tease at Matt’s nipples and loving the moan that slips past his lips as his hips buck up, kissing all the way down Matt’s stomach and tracing his v-lines with his tongue while palming at the bulge in the front of his jeans. Matt rolling his hips up in search of friction and hearing Matt groan his name is enough to make Kelly wanna move this along.

Kelly locks their lips together in a passionate kiss once more before lifting Matt up and carrying him to his bedroom, Matt kissing his neck and running his hands over his back the whole way.

Kelly drops Matt down on the bed and stares him down like a predator and his prey. Matt feels a shiver run up his spine in anticipation and can’t help but lick his lips as Kelly starts to slowly take off the rest of his clothes, frozen in place and just enjoying the show.

He’s so lost in the sight before him, admiring Kelly’s naked form, that he almost misses when Kelly growls. “Take your clothes off.”

Matt scrambles to get his clothes off as fast as humanly possible as Kelly just stands there, his face calm even as his dick is rock hard and wanting more.

Matt watches as Kelly slowly walks over to the bedside table and grabs lube and a condom, tossing them on the bed beside Matt. Kelly crawls over Matt, kissing from his hip up to his neck, their lips so close together and Matt’s about to close the gap again when Kelly growls once more.

“Roll over.”

Matt doesn’t even hesitate, so turned on by this dominant streak of Kelly’s and right now he couldn’t think of a single reason why this would ever be a bad idea.

Matt has no idea what to expect next, this was so different than the last time they had sex, that was frenzied and couldn’t slow down if you tried to but this was something else entirely. Matt’s brain and body are buzzing and it’s not rushed at all, it feels like Kelly has a plan and Matt’s just along for the ride and he can’t wait to find out what’s next.

Matt feels a hand run down the middle of his back and shivers at the gentle touch, then Kelly has both hands on his ass, squeezing and palming the flesh, Matt can feel the warmth of his breath and he thinks he knows what Kelly’s gonna do but that still doesn’t prepare him for the first lick of a hot, wet tongue over his hole.

Kelly will never forget the sound Matt just made, somewhere between a surprised yelp and a moan, Matt cants his hips back a little and that’s all the encouragement that Kelly needs. Pulling Matt’s hips back so he’s on his knees to give him better access, Kelly leans in to lick teasing circles around his rim. Matt moans into the pillow and Kelly smacks his ass, voice still deep and husky as he says.

“Don’t hide from me. I wanna hear you.”

Kelly gets back to it this time using the lube to slick his fingers and breaching that tight muscle with his tongue before slipping a finger inside and Matt rewards him with the most delicious groan.

Once Kelly’s up to three fingers Matt can’t keep quiet anymore, moaning and groaning as he pushes back on the fingers inside him.

“Kelly, you’re gonna make me cum.” Matt had meant it as a warning but Kelly sees it as a challenge. Purposefully pressing against Matt’s prostate as he pushes his fingers in, twisting as he pulls them out slowly, teasing his rim with flicks of his tongue until he forces the orgasm out of him.

Matt moaning Kelly’s name as he grips the pillow, shivers running down his spine as his thighs tremble, cumming untouched on the sheets beneath him as Kelly works him through his orgasm.

Kelly rolls Matt over to see the blissed-out look on his face as he comes back down to earth, kissing his neck and chest as he puts a condom on. Pushing his aching nine inches inside Matt in one smooth move, he groans at the tight heat as Matt gasps and wraps his arms around Kelly’s neck, clinging to him as his body buzzes, bordering on over sensitive and being too much but this is what he’d been dreaming of ever since that night, dreaming of feeling Kelly inside him once again.

Kelly starts a slow rhythm, more rolling his hips than actual thrusting, giving Matt a chance to adjust to his girth and he knew Matt had to be at least bordering on oversensitive right now. Kelly’s voice is still deep but his words are much softer than before as he leans down to whisper in his ear.

“If it’s too much I can stop.”

“Don’t you dare.” Matt moans as he wraps shaky legs around Kelly, pulling him in even closer and Kelly can feel Matt’s dick still rock hard against him, not even the slightest bit soft even after his orgasm.

Kelly sets the pace but Matt meets him thrust for thrust, he’s never seen anything so beautiful before, Matt completely lost to the moment, to the sensations, panting, moaning and groaning as a light sheen of sweat seems to make his body glisten. His head thrown back, exposing that long neck for Kelly to kiss and mark up when he can bare to turn his eyes away, Kelly’s more than pretty sure that come morning his back is gonna look like he got in a fight with a wild animal with the way Matt’s clinging to him, digging his nails in, pulling him in as close as possible.

Matt’s never felt anything like this before, he’s never had two orgasms so close together before yet he can feel it building up inside him again, he can feel Kelly everywhere and all at once and he’s so close to the edge but he’s not sure if he can cross it again so soon.

“K-Kelly, I’m – I’m – I don’t think I can –”

“Shh, shh, shh.” Kelly soothes, brushing stray hair of his forehead, kissing his lips sweetly as he reaches for Matt’s cock and says. “Trust me.”

Kelly’s jerking his cock in time with their thrusts and just hearing Kelly’s voice, those words ‘trust me’, there’s no one he trusts more and letting go of something deep inside him, he feels the most powerful orgasm of his life explode and ripple through his entire body.

Kelly’s been holding himself back for so long but seeing Matt’s face this time as he cums so hard and feeling the tightness around his dick instead of his fingers, he couldn’t have held back if he wanted to, cumming together as they hold onto each other.

Crawling under the sheets, cuddling together as they share in the afterglow, their lips joining in a sloppy kiss, they both know one thing is certain. This was never just a one-time thing.

**Author's Note:**

> I think I made Kelly a Dom, nothing kinky but he’s in total control. And I know I write totally unrealistic smut but I’ve come to realise that I don’t care, this is what fanfic was made for.


End file.
